The present disclosure relates to an image reading device and an image processing apparatus that are capable of performing processing at high speeds by effectively using a volatile memory.
In general, an image reading device includes a document sheet conveyance device and two reading devices. The document sheet conveyance device conveys a plurality of document sheets in sequence along a conveyance path. During a both-side reading process, the two reading devices read images from two surfaces of a document sheet at different positions in the conveyance path and output a plurality of pieces of line image data corresponding to the two surfaces in sequence, respectively.
When the image reading device performs a process of generating various types of image data from the plurality of pieces of line image data, processing-target data is primarily stored in a volatile memory with a fast access speed.
Each time a necessary piece of image data is generated, the generated piece of image data is transferred from the volatile memory to another device such as a secondary storage device, and after the image data becomes unnecessary, the image data is deleted from the volatile memory.
In addition, it is known that when the both-side reading process is performed, first image data is written into a region in a storage region of an image memory, and a writing start position of second image data is set after the region of the first image data. Subsequently, the second image data is written into the region of the image memory after the first image data is read therefrom.